Connector.



, .cowecwon APPLICATION FILED MAY ll. IBIS- Patented Mar; 19,1918.

nice.

GUY M. LAIRD, OF CHICAGO, ILLINOIS, ASSIGNOB OF ONE- HALF T0 LEO B.LINCOLN, OF

CHICAGO, ILLINOIS.

CONNECTOR.

Specification of Letters Patent. Patgnted Mar, 19, 1918,

Application filed May 11, 1916. Serial No. 96,762.

make and use the same, reference being had to the accompanying drawings,which form a part of this specification.

My invention has for its object to produce a simple, strong and durabledetachable cou pling orrconnector for electrical conductors which willgive good contact initially and will not become distorted and thus makepoor contact under long continued severe use or under careless handlingsuch as applying a transverse or bending force to the device as the twomembers are drawn apart.

The various features of novelty whereby my invention is characterizedwill hereinafter be pointed out with particularity in the claims; but,for a full understanding of my invention and of its object andadvantages, reference may be had to the following detailed descriptiontaken in connection with the accompanying drawing, wherein:

Figure 1 is an elevation of the two parts of a coupling or connectorembodying my invention, the two members being shown separated from eachother;

Fig. 2 is a view similar to Fig. 1 and showing the two members of thecoupling or connector engaged with each other;

Fig. 3 is a section taken on line 3-3 of Fig. 2;

Figs. 4 and 5 are views similar to Fig. 3, illustrating modifications;

Fig. 6 is a longitudinal section through a modified form of femalemember;

Fig. 7 is a transverse section through the member illustrated in Fig. 6,with the post engaged therewith; and n Fig. 8 is a view similar to Fig.6, illustrating a still further modification.

Referring to Figs. 1 to 5 of the drawing, 1 represents a post and 2 asleeve adapted to he slipped upon the post and make metallic contacttherewith so as electrically to connect conductors such as indicated at3 and 4, attached to the members 1 and 2 respectively.

Great dificulty has heretofore been experienced in securing andmaintaining good contact between the members of any comparatively simpledetachable connector or coupling because of wear and distortion of theparts even when used carefully, because of the setting of the metal inparts intended to give a spring action, and particularly because it maybe said that no device of this kmd ever receives careful usage. Forexample, where a device of this kind is used on a flat iron or otherelectrically heated household device, one member of the coupling orconnector will be jerked in almost any direction except that which willnot produce a lateral component tending to spread or bend the resilientmember.

In accordance with my invention I have made one of the members,preferably the sleeve, in such form that it will grip or press againstthe other member, when the two are brought together, with sufficientforce to-insure electrically-conductive continuity, will be stifi' andrigid enough for all purposes for which it is intended, and yet will beso flexible that rough careless handling of the device tending to bendand twist the same out of shape will produce no bad effect whatever. Iaccomplish this by making the resilient member in the form of a longstrip, preferably of spring metal, bent into the form of a helix of sucha diameter that a slight change in diameter results when the two membersare pressed together. The strip is preferably made wide as compared tothe thickness thereof and is wound so that the coils or turns lie closetogether and thus give the resilient member the appearance of a tubemade of a thin flat spirally wound strip. When the post is pushed intothe tubular member, the coils of the latter expand slightly, asillustrated in exaggerated manner in Fig. 2, gripping the post firmlywith a yielding pressure. The distortion of the spiral from its normalinactive condition is so slight that there is no possibility of.straining the material thereof sufiiciently to cause it to set.Furthermore, when the two members are pulled apart it makes littledifference whether the pull is straight or not because the spirallywound sleeve will yield and bond as it is drawn off the post if the pullis not a straight one. The bending stresses do not have to" be borne atany one point in the tube, however, because they are distributed notonly from one end of the tube to the other but from one end of thespirally wound strip tothe other end of the strip; and, the strip beingseveral times as long as the tube or sleeve, it will be evident that anyordinary amount of bending of the tube or sleeve resulting from anuneven pull in separating the two members of the connector, will haveonly a very slight effect on any given section of the long spring strip50- that there is no danger whatever of the tube or sleeve taking a setand failing to spring back to its normal position as soon as it isreleased from the bending pressure. 4

As I have heretofore stated I prefer to make the strip comparativelywide although I do not desire to be limited to a wide strip. With aconstruction of the kind illustrated the tendency is for the spiral togrip the post more tightly as the post is withdrawn and, if the materialbe very narrow it will be very difficult to separate the parts from eachother. By making the strip comparatively wide, however, the tendency ofthe outer member to close upon the inner member when the latter iswithdrawn therefrom is reduced to a point where it is not noticeable Iand allows the parts to be separated without While the two members ofthe device will ordinarily be made round in form, they may take anyother cross sectional shape; members, 5 and 6, one of which istriangular, corresponding to the members 1 and 2 being illustrated inFig. 4; and rectangular members, 7 and 8, being illustrated in Fig. 5.

In Figs. 6 to 8 I have illustrated-an arrangement in which the helix orspiral does not contact directly with the post, contact shoes beinginterposed between the sleeve and the ost.

Thus, in Figs. 6 and 7, the spiral 9, similarto the member, 2, of Figs.1 to 3, surrounds and bearsagainst a longitudinallysplit sleeve, 10, orwhat may be termed a,

slight modifications in cross sectional shape, 4

I do not desireto be limited to the exact structural details thusillustrated and described; but intend to cover all forms andarrangements which come within the terms employed in the definitions ofmy invention constituting the appended claims.

I claim:

1. A connector element comprising a tube made of a flat strip of springmetal wound in the form of a spiral.

2. A connector. element comprising a tube made of a piece of springmetal wound in the form of a spiral, and a contact piece fastened to andextending longitudinally through the tube and bearing against the wallthereof.

3. A device of the character described comprising two members adapted tobe telescoped on each other, one of said members being in the form of aspirally wound sleeve having a contact piece extending longitudinallythrough the same, and the other member being a post adapted to beinserted into the sleeve and yieldiugly held by the same against saidcontact piece.

4. A device of the character described comprising two members adaptedtobe telescopcd one upon the other, one of said members being a post andthe other member comprising a contact piece adapted to lie beside thelength of the ost surrounding the contact piece and a apted to press thesame against the post.-

5. A connector element comprising a tube made of a piece of spring metalwound in the form of a spiral, the cross section of said piece beingsuch that the inner surface of the tube is substantially continuous andsmooth.

6. A connector element comprising a tube made of a strip of spring metalhaving a fiat side, said strip being wound in the form of a spiral withthe flat side directed inwardly. v

7. A connector element comprising a tube made of a strip of spring metalhaving a flat side, said strip being wound in the form of a spiral withthe flat side directed inwardly, and a contact piece fastened to andextending longitudinally through the tube and bearing against the wallthereof.

8. A connector element comprising a tube made of a flat strip of springmetal wound in the form of a spiral the turns of which lie closetogether, the strip being of a greater width than thickness.

In testimony whereof, I sign this specification.

GUY M. mine.

85 i \and engage with the ost and a helical coil having its axisextending in the direction of

